The displacement or velocity of a loudspeaker diaphragm can be a useful parameter for evaluating the characteristics of any loudspeaker. Current techniques for measuring loudspeaker diaphragm displacement include using an optical sensor, for example a laser displacement sensor or transducer. Such sensors, however, suffer from various drawbacks including, for example, sensitivity to the surface characteristics of the target material (e.g., color, materials, etc.). In addition, with respect to other solutions such as placing an accelerometer on the loudspeaker diaphragm, the acceleration signal has to be integrated (to produce a velocity signal) and any noise in the measurement will cause an accumulated error.